An innovative micro-scale liquid desiccant dehumidification system is numerically investigated. The liquid desiccant dehumidification unit employs a counter-flow compact and efficient heat and mass exchange core enhancing the thermal performance and eliminating desiccant carryover with the process air. In addition, a chemically stable, non-corrosive, nontoxic and environmentally friendly HCOOK potassium formate liquid desiccant solution was employed in the unit. A set of governing differential equations was established for the dehumidification system operation allowing the development of a numerical model to predict and simulate the dehumidifier thermal performance and various output parameters. A numerical case study was considered for a micro-liquid desiccant dehumidification system using potassium formate and a dehumidification and cooling capacity of around 11.32 kW was attained with 59.35% humidity effectiveness and about 62.18% enthalpy effectiveness. In addition, a parametric study was performed to investigate the effect of various operational parameters on the overall performance of the liquid desiccant dehumidifier. Utilizing the developed numerical model, it was shown that the dehumidifier effectiveness is directly proportional to the intake air temperature, intake air relative humidity and liquid desiccant flow rate where the effectiveness is inversely proportional to the intake air velocity and the heat exchanger air channel height.